Electrochemical immunosensor, which is based on antibody-antigen binding, has received widespread recognition and interest due to its cost, simplicity, sensitivity, simple construction and feasibility of miniaturization (Thévenot et al., 1999; Ahmad et al., 2002; Ahmad et al., 2008; Saito et al., 2008; Ahmed et al., 2014). To increase the possibility of antibody-antigen binding and hence the sensitivity of an immunosensor, antibody can be immobilized at a specific site rather than at random orientation. Immunoglobulin, being a glycoprotein, possesses a branched oligosaccharide N-linked to asparagine 297 found in the Fc region. Because oligosaccharide moiety is facing away from the paratope (antigen-binding sites), this sugar moiety can be used for site-specific antibody immobilization without affecting antibody-antigen binding reaction (Sutton & Phillips, 1983). Ho and co-workers (2010) reported a simple method using boronic acid to form reversible cyclic covalent complexes with adjacent 1,2 or 1,3 diols (Springsteen & Wang, 2002) for immobilization of anti-biotin antibodies. However, electrochemical immunosensors cannot measure below a certain limit and thus needs improvement.